This invention relates to a device for providing a water tight seal between an electrical service cable as it enters the electrical service box mounted on an exterior surface of a house or other structure.
There is a long felt need to achieve a water tight seal between the electrical service cable and a meter box or other entrance box through which the cable enters the house or other structure and is interiorly connected to various circuits therein through an electrical panel box. In many cases, an adequate rain tight seal is not afforded between the entrance box entering the structure and the service cable and thus water enters the box and travels along the cable and into the interior electrical panel either directly shorting circuits or causing excessive rusting which eventually can cause the same problem. This situation can lead to a loss of power and more seriously to electrically caused fires, in fact, knowledgeable building inspectors attribute a high percentage of electrical fires caused in houses and other structures to this water leakage problem. Obviously, it would be desirable to avoid this problem by forming a water tight seal between the incoming electrical cable and the entrance box, and various attempts along this line have been made.
The most common attempt to solve the problem is to utilize silicone sealer, exterior caulking, duct sealer and many various potting compounds which are applied to the cable and over the mechanical attachment fitting which connects the cable to the entrance box and formed into a mountain or mound shape hoping it will shed water and become water tight. In many cases due to hot and cold temperatures creating expansion and contraction causes the sealing material to separate from the cable or because of ozone or ultraviolet sun light damage to the sealers cause them to dry up and deteriorate, various conditions are set up by which water can enter the interior panels and create dangerous conditions. In addition, the mechanical fitting used to mechanically attach the cable to the entrance box usually includes a rubber gland and compression fitting having a pair of laterally separated wings which receive the cable and which are tightened thereon with the use of screw threads and even though utilized in many instances in an attempt to achieve a weather tight connection between the service cable and the entrance box are not generally recognized as suitable for such purpose due primarily to the wide shape and tolerance variations permitted in the formation of various entrance service cable especially those of higher amperages, e.g., 100 amps and higher. These cables are generally of elongated flattened ovoid shape and often take the form of a figure eight in cross sectional configuration. Such elongated shapes that are subject to numerous size variations present an extremely difficult sealing task much more difficult and of a different scope than providing a seal between circular cable and an entrance box.
Various other attempts have been made to form water tight connective seals between cable members and downstream equipment to which they are attached including the common expedient of inserting a soft rubber insert between two members which are then tightened or providing a soft rubber member which engages a cable or wire but such latter concept as illustratively shown in U.S. Pat. No. 5,224,875 issued Jul. 6, 1993 is limited to cylindrical wires which are relatively easy to form a seal with respect to and even includes the use of a flexible diaphragm through which the wire or cable may extend through such as in the configuration depicted in U.S. Pat. No. 3,792,415 issued Feb. 12, 1974.
The above indicated attempts whether theoretically or actually in use do not, however, result in the desired water tight fit between the electrical service cable and the box to which it is attached to under actual field conditions. Accordingly, the need remains for a practical, low cost solution for this long standing industry problem.